.TH std::boyer_moore_horspool_searcher 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::boyer_moore_horspool_searcher \- std::boyer_moore_horspool_searcher

.SH Synopsis
   Defined in header <functional>
   template< class RandomIt1,

             class Hash = std::hash<typename
   std::iterator_traits<RandomIt1>::value_type>,                          \fI(since C++17)\fP
             class BinaryPredicate = std::equal_to<> >

   class boyer_moore_horspool_searcher;

   A searcher suitable for use with the Searcher overload of std::search that
   implements the Boyer-Moore-Horspool string searching algorithm.

   std::boyer_moore_horspool_searcher is CopyConstructible and CopyAssignable.

   RandomIt1 must meet the requirements of LegacyRandomAccessIterator.

.SH Member functions

std::boyer_moore_horspool_searcher::boyer_moore_horspool_searcher

   boyer_moore_horspool_searcher( RandomIt1 pat_first,

                                  RandomIt1 pat_last,
                                  Hash hf = Hash(),

                                  BinaryPredicate pred = BinaryPredicate() );

   Constructs a std::boyer_moore_horspool_searcher by storing copies of pat_first,
   pat_last, hf, and pred, setting up any necessary internal data structures.

   The value type of RandomIt1 must be DefaultConstructible, CopyConstructible and
   CopyAssignable.

   For any two values A and B of the type std::iterator_traits<RandomIt1>::value_type,
   if pred(A, B) == true, then hf(A) == hf(B) shall be true.

.SH Parameters

   pat_first, pat_last - a pair of iterators designating the string to be searched for
   hf                  - a callable object used to hash the elements of the string
   pred                - a callable object used to determine equality

.SH Exceptions

   Any exceptions thrown by

     * the copy constructor of RandomIt1;
     * the default constructor, copy constructor, or copy assignment operator of the
       value type of RandomIt1; or
     * the copy constructor or function call operator of BinaryPredicate or Hash.

   May also throw std::bad_alloc if additional memory required for internal data
   structures cannot be allocated.

std::boyer_moore_horspool_searcher::operator()

   template< class RandomIt2 >
   std::pair<RandomIt2, RandomIt2> operator()( RandomIt2 first, RandomIt2 last )
   const;

   The member function called by the Searcher overload of std::search to perform a
   search with this searcher. RandomIt2 must meet the requirements of
   LegacyRandomAccessIterator.

   RandomIt1 and RandomIt2 must have the same value type.

.SH Parameters

   first, last - a pair of iterators designating the string to be examined

.SH Return value

   If the pattern [pat_first, pat_last) is empty, returns std::make_pair(first, first).

   Otherwise, returns a pair of iterators to the first and one past last positions in
   [first, last) where a subsequence that compares equal to [pat_first, pat_last) as
   defined by pred is located, or std::make_pair(last, last) otherwise.

.SH Notes

         Feature-test macro        Value    Std    Feature
   __cpp_lib_boyer_moore_searcher 201603L \fI(C++17)\fP searchers

.SH Example


// Run this code

 #include <algorithm>
 #include <functional>
 #include <iomanip>
 #include <iostream>
 #include <string_view>

 int main()
 {
     constexpr std::string_view in =
         "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed "
         "do eiusmod tempor incididunt ut labore et dolore magna aliqua";

     const std::string_view needle{"pisci"};

     auto it = std::search(in.begin(), in.end(),
                   std::boyer_moore_horspool_searcher(
                       needle.begin(), needle.end()));
     if (it != in.end())
         std::cout << "The string " << std::quoted(needle) << " found at offset "
                   << it - in.begin() << '\\n';
     else
         std::cout << "The string " << std::quoted(needle) << " not found\\n";
 }

.SH Output:

 The string "pisci" found at offset 43

.SH See also

   search               searches for a range of elements
                        \fI(function template)\fP
   default_searcher     standard C++ library search algorithm implementation
   \fI(C++17)\fP              \fI(class template)\fP
   boyer_moore_searcher Boyer-Moore search algorithm implementation
   \fI(C++17)\fP              \fI(class template)\fP
